Metabolically Healthy Obese Persons Not So Healthy After All
There is no such thing as healthy obesity, according to a meta-analysis of 8 studies involving more than 60,000 adults.
Caroline K. Kramer, PhD, MD, a researcher at Mount Sinai Samuel Lunenfeld-Tanenbaum Research Institute in Toronto, Ontario, Canada, and colleagues reported their results in an article published online December 2 in Annals of Internal Medicine.
They looked at the incidence of cardiovascular disease (CVD) or all-cause mortality, comparing outcomes for both metabolically unhealthy and metabolically healthy people of various weights with outcomes for metabolically healthy people of normal weight.
In 8 studies with a follow-up period of 10 years or more, metabolically healthy obese (MHO) people had a relative risk (RR) for all-cause mortality and cardiovascular disease of 1.24 (95% confidence interval [CI], 1.02 – 1.55). The studies included 61,386 people and 3988 adverse events, and defined obesity as a body mass index (BMI) of 30 kg/m2 or greater, overweight as a BMI of 25 to 29.9 kg/m2 , and normal weight as a BMI of 18.5 to 24.9 kg/m2.
“Previous meta-analyses evaluating BMI and mortality have not considered the presence of metabolic factors, although excess mortality was already evident for obese individuals in some reports,” the authors write.
Those ranked “metabolically unhealthy” at any weight were at the highest risk for CVD and all-cause mortality. Metabolically unhealthy people of normal weight exhibited the highest RR (3.14; 95% CI, 2.36 – 3.93), followed by metabolically unhealthy overweight people (RR, 2.70; 95% CI, 2.08 – 3.30) and metabolically unhealthy obese people (RR, 2.65; 95% CI, 2.18 – 3.12).
Although adverse events were not apparent in MHO before 10 years, the authors note that excess weight is associated with short-term risk for subclinical vascular disease, including impaired vasoreactivity, left ventricular abnormalities, chronic inflammation, increased intima-media thickness of the carotid artery, and coronary calcification.
Taken together, these data suggest a model in which excess weight is associated initially with the development of subclinical metabolic and vascular dysfunction that ultimately leads to an increased incidence of CV events and mortality over the long term. In this regard, previous reports that evaluated metabolically healthy obese individuals over short-term follow-up or that compared these individuals to control groups not fully characterized for CV risk might have contributed to the concept of a ‘”benign obesity'” phenotype that is not associated with adverse outcomes. The results do not support this concept of ‘”benign obesity'” and demonstrate that there is no ‘”healthy'” pattern of obesity.
Dr. Kramer and colleagues advocate clinicians pay particular attention to metabolically unhealthy people of normal weight, who had as many adverse events as obese peers. This group “might represent the most severe subtype along the phenotypic spectrum of individuals genetically predisposed to CV disease.”
The analysis reveals one of several common misperceptions about obesity, write James O. Hill, PhD, executive director, and Holly R. Wyatt, MD, associate director, Anschutz Health and Wellness Center, University of Colorado, Aurora, in an accompanying editorial.
“First, the review casts doubt that any obese persons have no long-term risk for cardiometabolic disease,” the editorial states. “Obesity affects almost all aspects of human function and physiology.” Another misperception, they write, is the notion that “we cannot afford to treat everybody with obesity, so we have to prioritize those with cardiometabolic risk.” Such an approach would deny treatment to people who may later develop such risk, they note.
The data for the current meta-analysis came from prospective studies published between 2004 and 2011. Most studies judged metabolic health as absence of metabolic syndrome as defined by the Adult Treatment Panel III (ATP III) criteria or by the International Diabetes Federation (IDF). Other studies judged metabolic health as the presence of some components of the metabolic syndrome according to IDF or ATP III.
ATP III criteria for metabolic syndrome are a waist circumference of 88 cm or greater plus 2 of the following: a fasting triglyceride level of 1.69 mmol/L (>150 mg/dL), high-density lipoprotein cholesterol level less than 1.9 mmol/L (<50 mg/dL), systolic blood pressure greater than 130 mm Hg, diastolic blood pressure greater than 85 mm Hg, use of antihypertensive medicine, and fasting glucose level of 6.1 mmol/L or greater (≥110 mg/dL).
IDF criteria are a waist circumference of 94 cm or greater in men or 80 cm or greater in women plus 2 of the following: fasting triglyceride level of greater than 1.69 mmol/L (>150 mg/dL), high-density lipoprotein cholesterol level less than 1.04 mmol/L (<40 mg/dL) in men and less than 1.9 mmol/L (<50 mg/dL) in women, systolic blood pressure of 130 mm Hg or greater, diastolic blood pressure of 85 mm Hg or greater, antihypertensive medication, history of hypertension, fasting glucose level of 5.6 mmol/L or greater (≥100 mg/dL), or glucose-lowering medication.
Source
via Blogger http://chiropractic-lane.blogspot.com/2013/12/no-such-things-as-metabolically-healthy.html
Recent Comments